The present invention relates to copper pillar tin bump on semiconductor chip and method of forming of the same, and more particularly, through the simple progress of single photoresist patterning to compose the copper pillar tin bump, it's possible to simplify the progress and reduce the production costs.
Related prior patents are U.S. Pat. No. 7,183,648, USPub. 2006/0094226, U.S. Pat. No. 7,122,403, International Application No. PCT/US2004/040197.
These days, electronic products has been rapidly developed and it was caused by four factors, techniques of semiconductor designing, semiconductor packaging, semiconductor manufacturing, software programming.
A techniques of semiconductor designing includes composing over millions of cells, high speed data processing, heat radiation, composing line width under micron skills, but techniques of semiconductor packaging was relatively fall behind, so electric performance of semiconductor was determined by packaging and electric connectivity rather than it's performance.
Actually, over 50% of total electric signal delay of high speed electronic products occurs by packaging delay which is generated between chips, and expectedly, it's portion grows bigger to over 80% when systems get larger, so importance of packaging techniques becomes higher.
Recently, due to enhanced packaging performance, market demands on small size package, new substrate techniques and assembling progresses, semiconductor chip packaging market has been grown faster.
Such packaging techniques was solder paste screen painting by using screen printer, but it has limitation of minimum pattern size, restriction of minimum pitch of metal mask and solder paste printing resolution to make high density semiconductor chip packaging.
On the other hand, high density chip packaging techniques has been developed by using tin electroplating recently, but in this way, parasite resistance can be occurred by small packaging thickness between chip and board and thin insulation layer among boards, and it can have problem with durability because it is not good enough to be a mechanical stress absorption layer.